Smog and Pollutants

While mass production and the use of factories made many aspects of human life easier, it resulted in an increase in smog and pollution in cities. As industrial processes have advanced, smog has changed from everyday smoke to increasingly more dangerous chemicals, causing lung disease and cancer in humans as well as eroding buildings and crops. Understanding the nature of modern smog presents a compelling argument for reducing the amount of energy the human race consumes.

Ash

• The earliest form of smog came from burning fossil fuels like coal. Ash is released into the air as a thick black smoke which, if inhaled, can block airways and cause damage to the lungs. As well as containing carbon residue, ash contains silicon dioxide, calcium oxide and traces of heavy metals. According to the website Green-Planet-Solar-Energy.com, it is this silicon dioxide that can cause lesions, scarring and inflammation in the lungs. In 2011, most production plants now capture this ash before it is released into the air, though this is still a problem in less developed countries.

Sulfur Dioxide

• All fossil fuels contain sulfur dioxide, which is released when they burn. This highly reactive gas reacts with water to create sulfuric acid, commonly known as "acid rain." This acid rain can cause significant damage to crops, soil and buildings, but can also have adverse effects on human health. According to the Environmental Protection Agency, exposure to sulfur dioxide can cause respiratory problems, particularly in children, the elderly and those with asthma.

Nitrous Oxides

• Nitrous oxides are part of photochemical smog, a far more noxious form than the industrial smog of a hundred years ago. Nitrous oxides form following the reaction of oxygen gas and nitrogen gas, usually in the exhausts of cars. Because this takes place at ground level, on roads, the resultant smog is more easily inhaled by humans. Modern cars are now fitted with catalytic converters, which decrease the amount of nitrous oxide released.

Volatile Organic Compounds

• Volatile organic compounds are compounds that evaporate easily. It is commonly known that water evaporates at 100 degrees, turning into steam. Petrol evaporates far more quickly and is therefore described as "volatile." Other volatile organic compounds include methane, which is produced by cows and by hydroelectric energy power plants. These volatile organic compounds, particularly 1,3-butadiene and benzene, which are produced in car exhaust and industrial processes, are a health risk because they are carcinogenic.

Ozone

• Ozone has been such a concern in recent decades that most people will have heard of it. Its depletion in Earth's upper atmosphere can allow access to harmful radiation from the sun. Its production at ground level is a problem, however, because it is yet another respiratory irritant. It forms when nitrous oxides react with volatile organic compounds.